Local surface coils having radiofrequency antennas are used for acquiring radiofrequency signals and/or magnetic resonance signals for magnetic resonance examinations in combination with a positron emission tomography examination (PET examination). When magnetic resonance examinations are combined with PET examinations, a maximally precise knowledge of a position and/or an arrangement and/or a geometry of the surface coils is necessary in order to determine precisely a signal attenuation experienced by photons of a PET examination when passing through the surface coils. If surface coils are not taken into account in the attenuation correction, this can lead to missing PET events in the PET data and/or to image artifacts in the reconstructed image data. The difficulty that exists with regard to the attenuation correction of surface coils, however, is that the local surface coils can be arranged at different positions on the patient and are often embodied as flexible. For this reason surface coils often have an unknown geometry and/or unknown arrangement and/or unknown position during the examination.
An automatic method of detecting the position of surface coils by way of suitable additional markers is known from the publication by Kartmann et al. titled “Simultaneous PET/MR imaging: Automatic attenuation correction of flexible RF coils”, Proc. Intl. Soc. Mag. Reson. Med., 2013, 21, 0830. However, additional markers also mean additional investment of effort in the coil design and/or in the retrofitting of the surface coils. Furthermore, discrete magnetic resonance markers can be virtually convoluted into the magnetic resonance image in the course of a patient examination and thus simulate non-existent lesions.